
In loadView method:
//add a + button on the left
addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(addItem: )];
self.navigationItem.leftBarButtonItem = addButton;
//add a edit button on the right
self.navigationItem.rightBarButtonItem = self.editButtonItem;

-(void)setEdting:(bool)editing animated:(bool) animated {
	[super setEditing:edting animated:YES];
	if(editing) {
		addButton.enabled = NO;
	}else{
		addButton.enabled = YES;
	}
}
